NSAutoreleasePoolChecker.cpp revision 6f42b62b6194f53bcbc349f5d17388e1936535d7 
1//=- NSAutoreleasePoolChecker.cpp --------------------------------*- C++ -*-==//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file defines a NSAutoreleasePoolChecker, a small checker that warns
11//  about subpar uses of NSAutoreleasePool.  Note that while the check itself
12//  (in its current form) could be written as a flow-insensitive check, in
13//  can be potentially enhanced in the future with flow-sensitive information.
14//  It is also a good example of the CheckerVisitor interface.
15//
16//===----------------------------------------------------------------------===//
17
18#include "ClangSACheckers.h"
19#include "clang/StaticAnalyzer/Core/Checker.h"
20#include "clang/StaticAnalyzer/Core/CheckerManager.h"
21#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
22#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h"
23#include "clang/StaticAnalyzer/Core/PathSensitive/CheckerContext.h"
24#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h"
25#include "clang/StaticAnalyzer/Core/PathSensitive/ObjCMessage.h"
26#include "clang/AST/DeclObjC.h"
27#include "clang/AST/Decl.h"
28
29using namespace clang;
30using namespace ento;
31
32namespace {
33class NSAutoreleasePoolChecker
34  : public Checker<check::PreObjCMessage> {
35  mutable OwningPtr<BugType> BT;
36  mutable Selector releaseS;
37
38public:
39  void checkPreObjCMessage(ObjCMessage msg, CheckerContext &C) const;
40};
41
42} // end anonymous namespace
43
44void NSAutoreleasePoolChecker::checkPreObjCMessage(ObjCMessage msg,
45                                                   CheckerContext &C) const {
46
47  const Expr *receiver = msg.getInstanceReceiver();
48  if (!receiver)
49    return;
50
51  // FIXME: Enhance with value-tracking information instead of consulting
52  // the type of the expression.
53  const ObjCObjectPointerType* PT =
54    receiver->getType()->getAs<ObjCObjectPointerType>();
55
56  if (!PT)
57    return;
58  const ObjCInterfaceDecl *OD = PT->getInterfaceDecl();
59  if (!OD)
60    return;
61  if (!OD->getIdentifier()->getName().equals("NSAutoreleasePool"))
62    return;
63
64  if (releaseS.isNull())
65    releaseS = GetNullarySelector("release", C.getASTContext());
66  // Sending 'release' message?
67  if (msg.getSelector() != releaseS)
68    return;
69
70  if (!BT)
71    BT.reset(new BugType("Use -drain instead of -release",
72                         "API Upgrade (Apple)"));
73
74  ExplodedNode *N = C.addTransition();
75  if (!N) {
76    assert(0);
77    return;
78  }
79
80  BugReport *Report = new BugReport(*BT, "Use -drain instead of -release when "
81    "using NSAutoreleasePool and garbage collection", N);
82  Report->addRange(msg.getSourceRange());
83  C.EmitReport(Report);
84}
85
86void ento::registerNSAutoreleasePoolChecker(CheckerManager &mgr) {
87  if (mgr.getLangOptions().getGC() != LangOptions::NonGC)
88    mgr.registerChecker<NSAutoreleasePoolChecker>();
89}
90